1. Field of the Invention
The present invention relates to a superconducting apparatus in which an element that exhibits the superconducting phenomenon and a cooling element are combined together.
2. Description of the Prior Art
As is conventionally known, the superconducting phenomenon that certain types of conductive materials, when cryogenically cooled, show zero electric resistance appears when, for example, lead or a niobium alloy is cooled to cryogenic temperature around the liquid helium temperature. Accordingly, when such a superconducting phenomenon is applied to switching devices or high-sensitivity sensor devices, a high-speed, high-sensitivity operation can be implemented without causing any power loss to a greatly remarkable advantage. On the other hand, however, there arises a need of cooling such devices to cryogenic temperatures. In such cases, the devices must be used as they are accommodated in a cooling unit, so called cryostat, using liquid helium and liquid nitrogen. The cooling unit, being large, complex, and expensive, makes a great obstacle to the practicability of the superconducting systems. At present, this problem has not been solved yet, so that the superconducting phenomenon is not widely or commonly used as it stands.
In recent years, there have emerged oxide materials one after another that exhibit a new superconducting phenomenon. Use of these materials, it is expected, will allow superconducting apparatus to be provided at low temperatures closer to room temperature.
However, even if these materials are used, it is indispensable to add cooling means capable of substantially low temperature cooling, in order to make a superconducting phenomenon occur with good reproducibility and thereby impart high reliability to the apparatus. As a result, the whole apparatus would be large in size and high in price.
To solve the above problems, the present inventor has filed an application of patent for a superconducting apparatus in which a superconducting element is disposed on a cooling portion of a Peltier effect element and accommodated in a container (see Japanese Patent Laid-open Publication No. SHO 64-18280).
The aforementioned patent application has also proposed that the container interior is sealed by an inert gas atmosphere. In this case, indeed the device reliability is improved by sealing with the inert gas, but the container would be cooled due to the presence of the inert gas. It would therefore be the actual case, for example, that the cooling efficiency is deteriorated or that moisture in air condenses as dew to stick to the container, disadvantageously.